Etcher for semiconductor manufacturing

ABSTRACT

The present invention provides an etcher for semiconductor manufacturing. The etcher comprises a chamber for accepting a wafer, having an inlet and outlet through which a gas is pumped into and out of the chamber, first and second electrodes generating an electrical field to ionize the gas for reacting with the wafer, and a plate disposed between the inlet and outlet, deflecting the gas flow therebetween.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an etcher for semiconductormanufacturing, particularly to an etcher having a plate deflecting thegas flow in the chamber to eliminate teeth defects on the wafer.

[0003] 2. Description of the Prior Art

[0004]FIG. 1 is a diagram showing a conventional plasma etcher. Theplasma etcher comprises a cylindrical chamber 11 having an inlet 14 andoutlet 15, a positive electrode 12, and a negative electrode 13. A wafer16 disposed on a boat 17 is accepted by the chamber 11.

[0005] The operation of the plasma etcher will be explained.

[0006] The boat 17 carrying the wafer 16 is pushed into the chamber 11.The air in the chamber 11 is then extracted to form a vacuum and a gas(a combination of oxygen and CF₄ for example) for etching reaction ispumped into the chamber 11 through the inlet 14. An electrical field isgenerated by and between the positive and negative electrodes 12 and 13.Thus, the gas in the chamber 11 is ionized and becomes a plasma reactingwith the wafer 16. The un-reacted and reacted gas are continuouslypumped into and out of the chamber 11 through the inlet 14 and outlet 15respectively to maintain a proper gas pressure and concentration duringthe reaction.

[0007] The arrows in the FIG. 1 show a gas flow in the chamber 11resulting from the continuous pumping of the gas. The gas almost flowsfrom the inlet 14 to the outlet 15 in the same direction.

[0008] However, the gas is not well distributed and does not stay toolong in the chamber 11 since the gas flow is directly from the inlet 14to the outlet 15. This results in teeth defects on the periphery of thewafer 16.

SUMMARY OF THE INVENTION

[0009] Therefore, the object of the present invention is to provide anetcher for semiconductor manufacturing, wherein the gas flow in thechamber is deflected by a plate so that the gas is well distributed andthe teeth defects are prevented.

[0010] The present invention provides an etcher for semiconductormanufacturing. The etcher comprises a chamber for accepting a wafer,having an inlet and outlet through which a gas is pumped into thechamber, first and second electrodes generating an electrical field toionize the gas for reacting with the wafer, and the reacted gas ispumped out from the chamber through the outlet, and a plate disposedbetween the inlet and outlet, and deflecting a gas flow therebetween.The present invention further may further provide a plurality of holesdisposed in the plate, through which the reacted gas flows to theoutlet.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The following detailed description, given by way of example andnot intended to limit the invention solely to the embodiments describedherein, will best be understood in conjunction with the accompanyingdrawings, in which:

[0012]FIG. 1 is a diagram showing a conventional plasma etcher.

[0013]FIG. 2 is a diagram showing a plasma etcher according to oneembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0014]FIG. 2 is a diagram showing a plasma etcher according to oneembodiment of the invention. The plasma etcher comprises a cylindricalchamber 21 having an inlet 24 and outlet 25, a positive electrode 22, anegative electrode 23, and a plate 28 having holes 281 and 282. A wafer26 disposed on a boat 27 is accepted by the chamber 21.

[0015] The operation of the plasma etcher will be explained.

[0016] The boat 27 carrying the wafer 26 is pushed into the chamber 21.The air in the chamber 21 is then extracted to form a vacuum and a gas(a combination of oxygen and CF₄ for example) for etching reaction ispumped into the chamber 21 through the inlet 24. An electrical field isgenerated by and between the positive and negative electrodes 22 and 23.Thus, the gas in the chamber 21 is ionized and becomes a plasma reactingwith the wafer 26. The un-reacted and reacted gas are continuouslypumped into and out from the chamber 21 through the inlet 24 and outlet25 to maintain a proper gas pressure and concentration during thereaction.

[0017] The arrows in the FIG. 2 show gas flow into the chamber 11resulting from the continuous pumping of the gas. There is turbulence inthe gas flow since the gas pumped into the chamber is blocked by theplate 28. The plate 28 deflects the gas flow. This makes distributes thegas more thoroughly and keeps it longer in the chamber 21. The reactedgas then flows through the holes 281 and 282 to the outlet 25 and ispumped out from the chamber 21. Teeth defects on the periphery of thewafer 26 are thus eliminated.

[0018] In conclusion, in the invention, a plate deflects the gas flow inthe chamber so that the gas is well distributed and stays longertherein, whereby teeth defects on the periphery of the wafer areprevented.

[0019] While the invention has been described by way of example and interms of the preferred embodiment, it is to be understood that theinvention is not limited to the disclosed embodiments. On the contrary,it is intended to cover various modifications and similar arrangementsas would be apparent to those skilled in the art. Therefore, the scopeof the appended claims should be accorded the broadest interpretation soas to encompass all such modifications and similar arrangements.

What is claimed is:
 1. An etcher for semiconductor manufacturingcomprising: a chamber for accepting a wafer, having an inlet and outletthrough which a gas is pumped into and out of the chamber respectively;a first and second electrodes generating an electrical field to ionizethe gas for reacting with the wafer; and a plate disposed between theinlet and outlet, deflecting the gas flow therebetween.
 2. The etcher asclaimed in claim 1 wherein the chamber is a cylindrical chamber.
 3. Theetcher as claimed in claim 1 wherein the chamber further accepts a boaton which the wafer is disposed.
 4. The etcher as claimed in claim 1wherein the gas is a combination of oxygen and CF₄.
 5. The etcher asclaimed in claim 1 wherein the plate is made of quartz.
 6. An etcher forsemiconductor manufacturing comprising: a chamber for accepting a wafer,having an inlet and outlet through which a gas is pumped into and out ofthe chamber respectively; a first and second electrodes generating anelectrical field to ionize the gas for reacting with the wafer; and aplate disposed between the inlet and outlet, deflecting the gas flowtherebetween, and having a plurality of holes through which the reactedgas flows to the outlet.
 7. The etcher as claimed in claim 6 wherein thechamber is a cylindrical chamber.
 8. The etcher as claimed in claim 6wherein the chamber further accepts a boat on which the wafer isdisposed.
 9. The etcher as claimed in claim 6 wherein the gas is acombination of oxygen and CF₄.
 10. The etcher as claimed in claim 6wherein the plate is made of quartz.